Pressure regulator incorporating a pressure balanced moving seat

ABSTRACT

An adjustable pressure control valve includes a body having an inlet port and an outlet port and a handle assembly having a threaded portion and an adjustment knob. A seat assembly disposed within the body includes a seat holder in communication with the outlet port that is received on the threaded portion of the handle assembly, wherein the seat holder is translatable in first and second directions when the handle assembly is rotated in first and second directions. The seat assembly also includes a valve seat fluidly affixed to the seat holder, wherein fluid can pass through the valve seat and the seat holder. The valve includes a pin biased by a pin spring that is engageable with the valve seat, and a main spring engageable with the pin to urge the pin against the valve seat to accommodate the pressure and volume of the fluid in the valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/973,772, filed on Oct. 26, 2004, which claims the benefit of U.S.Provisional Application No. 60/515,930, filed on Oct. 30, 2003, thespecifications of which are hereby expressly incorporated by reference.

BACKGROUND

Most pressure regulator designs are based on the concept of anadjustable orifice that is controlled by using an adjustable spring biasto provide a pressure set-point. The principle difference in previousdesigns of these devices is centered on the method by which the springbias is applied.

The most common technique for biasing a spring is to apply forcedirectly to the spring by means of an adjusting screw. This techniquerequires that the device must overcome the force of the spring, as wellas the system pressure, and it is the least efficient. A typical controldevice consists of a pin and seat which, working with a bias spring,provides a controlled orifice.

For low pressure, the down side of using this technique is relativelysmall, and the complexity of the valve is minimal. For high pressure,the force of adjustment becomes more problematical and thus, othertechniques to artificially bias the spring are used. In some cases, theseat is adjusted independently relative to the control pin, whichartificially biases the springs. In other cases, the pin is biasedrelative to the spring by changing its relationship to the seat.

There are a number of pressure regulators that employ a moving seatconceived to overcome some of the shortcomings of the previoustechnology. The major improvement introduced here is to change, themethod of biasing the piston spring set. In previous patentedtechnologies, either the springs were adjusted from an external source,or a moving seat was employed to achieve the same result. In both cases,it was necessary to overcome the system pressure in order to make anadjustment, which resulted in high torque loads needing to be appliedfor any adjusting screws

The previous technology which most closely resembles this PBMS designemploys a moving seat to change the bias of the springs, thus changingthe pressure control set-point. This technology relies on minimizing thearea of the moving seat that is exposed to the system pressure. Thereis, however, still an imbalance between the atmospheric pressure and thesystem pressure, which changes the volume of the valve duringadjustment. The force necessary to displace the fluid at high pressurecan still be very significant.

The potentially patentable aspect of the PBMS technology is that themoving seat does not change the internal volume of the device. Thus, inadjusting the device, no static pressure imbalance has to be overcome,as is the case in previous technology. This concept provides a means toadjust the pressure regulation set-point with minimal force. For highpressures, this is very significant, especially if remote-controlactuation is desired.

The present invention provides adjustable pressure control valves forcontrolling pressure of a fluid from a fluid supply. The valves of thepresent invention can accurately regulate a wide range of pressures andrequire a relatively small amount of torque to adjust the pressure ofthe valve during operation. The valves of the present invention includea unique pressure balance moving seat which sets it apart from previoustechnology. The unique design of the adjustable pressure control valvesof the present invention make it possible to accurately regulate a widerange of fluid pressures without changing the configuration of thevalves.

The unique patentable aspect of the PBMS technology is that the movingseat does not change the internal fluid volume of the device. Thus, inadjusting the device, no static pressure imbalance has to be overcome,as is the case in previous technology. This concept provides a means toadjust the pressure regulation set-point with minimal force. For highpressures, this is very significant, especially if remote-controlactuation is desired.

The valve consists of five major components.

First, the body which houses all of the functioning components.

Second, the adjustment handle assembly which passes through the body. Ithas a thread engagement on one end and an adjustment knob on the other.This assembly can rotate within the housing, but does not translate.

Third, the seat assembly which consists of a valve seat on one end ofthe housing and a thread engagement on the opposite end of the housing.The thread engages the threaded end of the handle assembly. The seatassembly also includes seals which isolate the outlet port from any flowpath other than through the seat. Additionally, there is a flow paththrough the seat housing which allows fluid to pass through the housingin either direction when the housing is translated via the threadengagement with the handle assembly.

Fourth, the pin assembly which consists of a pin that is designed toengage the seat at varying distances, depending upon the pressure andvolume being regulated through the valve. The pin assembly consists of apin and a housing that permits the pin to translate within the housing.The pin is biased via a spring. The purpose of this translation is toprevent the pin and seat from being damaged when fluid pressure is notpresent in the valve.

Fifth, the valve spring assembly which consists of the main spring stackand housing. This spring stack provides the necessary force to providethe required regulation.

The functionality of the valve is as follows: When fluid is introducedinto the inlet port, it passes through the seat contained within theseat housing and exits through the outlet port. A restriction can beinduced at the seat by translating the seat in the direction of the pinassembly. As the pin moves into the seat, the volume of fluid that canpass through the seat is decreased.

It should be noted that the pin contained within the pin assembly isbiased, as noted above, by a spring. It also is biased by the pressureof the fluid that is introduced into the valve. Therefore, the force onthe pin is equal to the fluid valve pressure force plus the springpressure force. This prevents the pin from translating within itshousing. This combined force prevents the pin from translating withinits housing during operation.

The pressure of the fluid being restricted then causes the pin assemblyto translate against the bias of the main spring. The combination of theforce of the main spring, the restriction, and the fluid pressureresults in a pressure balance which is maintained by the proximity ofthe seat and the pin to each other. The pin translates relative to theseat to maintain a set pressure.

The control valve of the present invention is capable of accuratelyregulating fluid pressures at any set pressure. This particularembodiment is especially useful for regulating very high pressures,because there is no change in volume of fluid within the valve when anadjustment is made. This adjustment feature is unique to this presentinvention.

The torque requirement needed to operate the valve is largely a functionof a change in seal pressure as the pressure is increased. Therefore,the torque required to turn the adjustment handle is fairlyinsignificant throughout the whole pressure range. This attribute of thepresent invention makes the valve easily adaptable to automation usinglow energy actuators. The valve size can be scaled up or down with nolimit outside of the practical applications.

While this design is primarily for liquids, the same technology could beapplied to a gas regulator, as the principles hold for either type offluid.

SUMMARY

An adjustable pressure control valve includes a body having an inletport and an outlet port and a handle assembly having a threaded portionand an adjustment knob. A seat assembly disposed within the bodyincludes a seat holder in communication with the outlet port that isreceived on the threaded portion of the handle assembly, wherein theseat holder is translatable in first and second directions when thehandle assembly is rotated in first and second directions. The seatassembly also includes a valve seat fluidly affixed to the seat holder,wherein fluid can pass through the valve seat and the seat holder. Thevalve includes a pin biased by a pin spring that is engageable with thevalve seat, and a main spring engageable with the pin to urge the pinagainst the valve seat to accommodate the pressure and volume of thefluid in the valve.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This summary is not intended to identify key features ofthe claimed subject matter, nor is it intended to be used as an aid indetermining the scope of the claimed subject matter.

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thepresent disclosure will become more readily appreciated by reference tothe following detailed description, when taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a cross-sectional schematic side view of a pressure regulatorconstructed in accordance with one embodiment of the present disclosure;

FIG. 2 is a cross-sectional side view of the pressure regulator of FIG.1, showing a fluid flow path of fluid through the pressure regulator ofFIG. 1;

FIG. 3 is a cross-sectional view of a prior art pressure regulator;

FIG. 4 is a cross-sectional side view of the pressure regulator of FIG.1;

FIG. 5A is a cross-sectional side view of the pressure regulator of FIG.4, showing the flow path of fluid through the pressure regulator;

FIG. 5B is a cross-sectional side view of the pressure regulator of FIG.4 rotated 90 degrees from the position illustrated in FIG. 4;

FIG. 6 is an isometric exploded view of a pin subassembly of thepressure regulator of FIG. 4; and

FIG. 7 is an isometric exploded view of a seat subassembly of thepressure regulator of FIG. 4.

DETAILED DESCRIPTION

The embodiment of the PBMS for a pressure regulator application is asfollows:

Referring to FIG. 1, the valve constructed in accordance with oneembodiment of the present disclosure includes of a body (1) that housesall of the functioning components, and an adjustment handle (2) thatrotates within the body, but does not translate. This adjustment handlehas a threaded portion (3) that connects it to the moving seat assembly(4). The seat assembly (4) includes a seat (11) contained within theseat assembly (4) and is sealed on both ends by seals (5) and (6). Thisseat assembly (4) can translate via the threaded portion (3) to adjustthe relative position of the seat (11) to a piston/pin (7). Between theseals (5) and (6) that are embodied in the moving seat is the outletport (12) of the device. The piston/pin (7) is sealed from theatmosphere by a seal (9). The piston/pin (7) is biased by a spring (8).

When pressure is introduced via the inlet port (10), the piston/pin (7)is displaced against the bias of the spring (8). The position of theseat assembly (4) and seat (11) can be adjusted via the adjustmenthandle (2). This adjustment controls the size of the fluid passageway.Referring to FIG. 2, there is a passage (X) through the moving seatassembly (4) which allows fluid to be equally pressurized on either sideof the moving seat assembly (4). Also note that the areas (A) and (B)are equivalent; thus, the seat is in balance in terms of staticpressure.

Referring to FIG. 3, previous technology shows how the moving seat isnot in balance, as one end is at atmospheric pressure (P), while theother is at system pressure (S). When the seat is moved forward, as isthe case in previous technology, it must displace the volume at systempressure. This requires a much higher input force.

Referring to FIGS. 4-7, the body (1) is a pressure vessel which includesan inlet port (10) and an outlet port (12) and has a bore in which themoving parts can translate. FIG. 5A shows the flow path of fluid throughthe pressure regulator.

Referring to FIGS. 6 and 7, there are two sub assemblies within the body(1): A pin sub assembly (35) (FIG. 6) and a seat sub assembly (4) (FIG.7). These two sub assemblies are made up of components which form anadjustable passageway. This passageway is of a pin (7) and seat (11)design in which the seat (11) has a fixed orifice, and the pin (7) ispositioned at varying distances within that orifice to change the areaof the passageway.

Referring to FIG. 4, the two sub assemblies can both translate relativeto each other. The pin sub assembly (35) passes through a device calleda cartridge (13) and is positioned by a spring (8). The pin sub assembly(35) is free to translate through the cartridge (13). The cartridge (13)positions the pin sub assembly (35) within the body (1) in conjunctionwith a variety of seals (2), (9), (34), and (14). This forms a closureelement to the atmosphere for the body (1).

At the point where the pin sub assembly (35) exits the cartridge (13),it is trapped by a receiver (18). This receiver (18) is biased against aspring stack (8) which is contained within the spring housing (16). Thereceiver (18) is free to translate within the spring housing (16). Inturn, the spring housing (16) is threaded to the body (1) and capturesthe cartridge (13), locking it into place.

The pin sub assembly (35) is comprised of a slider (19), a spring (20),a slider cap (23), a pin housing (24), the pin (7) and a pin retainer(21).

The slider (19) and slider cap (23) are threaded together. The slidercap (23) holds the pin (7) and the pin housing (24) in position. The pin(7) and pin housing (24) are biased against the spring (20).

The pin (7) and pin housing (24) are free to translate within the spaceformed by the slider (19) and the slider cap (23).

The volume formed by the slider (19) and the slider cap (23) is notsealed from the internal pressure of the valve.

The purpose of this spring-biased sliding mechanism is to allow thespring stack (8) to fully extend when pressure is absent from the valveto prevent the pin (7) from being damaged.

Referring to FIG. 7, the seat sub assembly (4) consists of a seat holder(27), the seat (7) which embodies an orifice, a seat retainer (8), and aset of seals (5) and (25) that prevent fluid from flowing to the outletport (12), thus ensuring that all the fluid passes through the orificein the seat (7).

Referring to FIG. 4, the seat sub assembly (4) is engaged by a threadedstem (3), which is captured by the body (1) and is free to rotate withinthe body (1). This rotational motion allows the seat sub assembly (4)(FIG. 7) to translate within the body (1), thus changing the positionrelative to the pin (7) and thereby changing the size of the passageway.This allows a pressure set-point to be achieved.

Referring to FIG. 5B, the threaded stem (3) is manifolded through aseries of drilled passages 40, 42, and 43 to allow pressureequalization. This minimizes the torque requirement needed to move theseat sub assembly (4). The seat sub assembly (4) also is manifoldedthrough a series of drillings 44 and 46. This allow fluid pressure to beequalized around the seat sub assembly (4). The drillings 40, 42, 43, 44and 46 allow the seat sub assembly (4) to translate within the valvefreely, as there is no change in volume when the seat sub assembly (4)(FIG. 7) is translated.

The internal pressure of the valve is maintained through a variety ofseals (2), (9), (34), and (14).

Additionally, there is an adjustment handle (2) fixed to the threadedstem (3). The threaded stem (3) is pressure biased against a bearing(31) which allows the threaded stem (3) to rotate freely.

There is also a panel nut (29) which provides a means of mounting thevalve to a control panel, an air vent (17) and a dust seal (22).

While illustrative embodiments have been illustrated and described, itwill be appreciated that various changes can be made therein withoutdeparting from the spirit and scope of the present disclosure.

The embodiments of the present disclosure in which an exclusive propertyor privilege is claimed are defined as follows:

1. An adjustable pressure control valve for controlling fluid from afluid supply, comprising: (a) a body having an inlet port and an outletport, the inlet port adapted to be placed into communication with afluid supply; (b) a handle having a threaded portion disposed within thebody and an adjustment knob positioned outside the body; (c) a seatassembly disposed within the body, the seat assembly comprising: (i) aseat holder in fluid communication with the outlet port, the seat holderhaving first and second ends, the first end of the seat holderthreadably received on the threaded portion of the handle, wherein theseat holder is moveable in a first direction when the handle is rotatedin a first rotation direction and moveable in a second direction whenthe handle is rotated in a second rotation direction, wherein the seatholder allows a predetermined amount of fluid to pass therethrough whenthe seat holder is translated in the first and second directions; and(ii) a valve seat affixed to the second end of the seat holder; (d) apin assembly at least partially disposed within the body, the pinassembly having a pin biased by a pin spring such that the pin isengageable with an opening in the valve seat; and (e) a valve springassembly having a spring housing coupled to the body and a main springdisposed within the spring housing, the main spring engageable with thepin assembly to urge the pin against the valve seat to accommodate thepressure and volume of fluid in the valve.